This invention pertains to computer systems and other information handling systems and, more particularly, to a computer system which is capable of detecting the type of fan being used in the system.
Generally, a computer system includes a board with various Large Scale Integration (LSI) chips such as a processor mounted thereon, a storage device such as a hard disk, a battery device, and input/output devices, each of which is known to generate heat as each operates in a computer. For some electrical components, such as a processor, a temperature range is often indicated by specifications which set a temperature range indicative of satisfactory and/or optimum performance (hereinafter, as used herein, this temperature and range may also be referred to as “rated temperature”), and often one or more cooling fans are typically provided in conjunction with electrical components in a computer system to keep the temperature in the system within the rated temperature.
A computer system may include multiple processors or electrical components that each need to be cooled by a different cooling fan. The speed of each of these cooling fans may be controlled by a program embedded in the system Basic Input/Output System (BIOS) code. Typically, the speed of each of these fans is controlled by a pulse width modulated signal at an input terminal of the more modern fans, and by pulsing a supply voltage to the fan in older fans. The pulse supplied to the older fans may vary based on the width, amplitude and frequency of the pulse. These characteristics (PWM input, and power supply pulse width, amplitude and frequency) may all be used to control the speed of the cooling fan.
Cooling fans may be manufactured from different manufacturers and may include different designs that each has specific PWM characteristics or, in the case of older fans, supply voltage characteristic requirements for optimum performance.